The excretory system is a vital component of the human body that is responsible for removing metabolic wastes, maintaining fluid and electrolyte balance, and regulating internal homeostasis. It consists of several organs that work together to eliminate harmful substances produced during cellular activities. The primary organs of the excretory system include the kidneys, ureters, urinary bladder, and urethra, while auxiliary organs such as the skin, lungs, and liver also contribute to excretion. The kidneys are the main excretory organs, located on either side of the vertebral column. Each kidney contains millions of microscopic units called nephrons, which are responsible for filtering blood. The process of urine formation in the kidneys involves three main steps: filtration, reabsorption, and secretion. During filtration, blood is filtered in the glomerulus, allowing water, salts, glucose, and waste products like urea to pass into the renal tubule. In reabsorption, useful substances such as glucose, amino acids, and certain ions are reabsorbed back into the bloodstream. Secretion involves the transfer of additional waste substances from the blood into the tubular fluid. The final product, urine,